Hydraulic turbine



March 5, 1929. w. s wE 1,704,223

HYDRAULIC TURBINE Filed June 6, 1927 3 Sheets-Sheet l Wyn/7w March 5, 1929. w, s w 1,704,223

HYDRAULIC TURBINE Filed June 6, 192'? 3 Sheets-Sheet 2 wvzmm Ami/VD 3 Sheets-Sheet Filed June 192 rection.

Patented Mar. 5, 1929.

UNITED] STATES PATENT OFFICE.

PAUL wnimnasnnwna, or Lo DoN, ENGLAND. ASSIGNOR TO THanNGLIsn nLncrare COMPANY, LIMITED, or LoNDoN, ENGLAND, A BRITISH coMrANY;

HYDRAULIC TURBINE Application filed June 6, 1927, Serial No. 196,952, and in Great Britain June 18, 1926. a

lVhere it is desired to shut down a hydraulic reaction turbine particularly when coupled to an electric generator it is necessary to provide some means of absorb ng quickly the energy stored in the rotatlng masses in order that they maybe brought to rest within a short time. With this in view it has been the practice to provide mechanical brakes to be applied to rotating surfaces and produce the absorption of the energy by solid friction. In accordance with the present invention a hydraulic brake is provided. This is done by projecting free jets of water against the blading of the ru nner of a reaction turbine in such a direction or directions as to produce on the runner impulses which oppose its rotation in the normal running direction. These jets can be brought into action on the outlet side of the runner and may be directed towards the runner either axially or transversely. The former arrangement is particularly suitable in the case where the draught tube is bent as commonly the case with turbines which have the shaft horizontal. Transversely directed ets can be conveniently used with any form of draught tube since they can be projected from the side wall of this tube a short distance away from the outlet surfaces of the runner.

The preferable arrangement of the axial jets is that in which a single jet is used mounted in the bend of the draught tube at a point directly in line with the axis of the runner. The jet will then strike on the end of the runner which will have a conical centre by which the jet will be deflected laterally. The deflected jet encounters the back surfaces of the blades which are so formed that the pressure of the jets upon them will produce a tangential component opposing rotation in the normal runn ng di- WVhere transversel directed jets are employed they are pre erably arranged in the wall ofthe draught tube or adjacent parts of the turbine structure just outside the outlet end of the'runner. In this case it may probably be more advantageous to use several jets thana single jet each jet beingin a direction which is to a large degree transverse but also contains an axial component so as to cause it to enter the s aces surrounded by the outlet parts of t e runner vanes and to pass across the runner centre (preferably without encountering itto any extent) and then impinge upon the backs of the vanes as near as may be desired to those parts of the outlet edges Wherethe vanes adjoin thecentre of the runner. By this means the jets are caused to exert impulses on thevanes which have tangential components which oppose the normal direction.

of rotation. v k The jets may be formedas out-lets from an annular channel arrangedin the lower end of the speed ring or otherconvenient position, and can be normallyclosed by some form of stop valves,for instance, flaps each of which is thrown open by the action of the jet-when it is being brou ht into action.

The jets are supplie with water preferably from a point in the pipe line above I the main valve which controls theturbine supply, or from some other source of supply and can be brought into action automatically or otherwise by opening a valve in the con: i

necting pipe. Itwill be understood that the valve will only be brought into action after the runner casin and draught tube have be come emptied 0 water. a

y Inaddition to ,the impulse. action. previously described, the hydraulic braking action will also be brought about to a certain extent by the pumping action of the runner employing that part of the water from the jet which enters the spaces between the vanes and is retained thereowing tocentrifugal action due to the rotation of the runner. Two embodiments of the invention will now bedescribed by Way of example with reference to the accompanying drawings ot which Figure 1 shows a sectional elevation on the line II of Figure 2 the runner and a draught tube, and co-actin g. Sal-ts of a re action turbine having a vertica shaft. Figs. are 2 shows aplan on theline II-JIOf Figure 1 which is the floorlevcl of the turbine Figure 3 shows a central sectional elevation of a reaction turbine havinga horizontalshaft. I 3 i j Referring to Figures 1 and, 2 the runner and its blades are denoted respectively by the numeralsl. and2 and the former is attached in known manner to the lower end of a vertical shaft (not shown) which is attached at its upper end to the rotor of a dynamo electric machine (not shown) mounted upon a foundation indicated by the chain dotted lines 3. The arrangements of j these turbines are quite well known and the drawings therefore are only intended to show fully those parts which havea direct connection with thepresent invention. The water is delivered to the blades 2 of the runner from a spiral casing (not shown) which is disposed around the runner 1 in known manner. The casing itseli is supplied with water through the conduit pipe l which is :onneeted to a pipe line (not shown) through a main valve 14-.

In accordance with the invention a. tree jet of water 13 is caused to' strike the under side of the runner blades 2 in a suitable direction to supply the necessary braking effort. This jet is delivered from a nozzle denoted by the numerals 9 and 10 which is fixed to the wall of the upper circular part of the draught tube 6 so that it projects but slightly into the water-way of this part. The nozzle is connected to a pipe 7 and the water is delivered through this pipe from the pipe-lino side of the main valve 14 under the control of ahand operated sluice valve 8.

Before applying the hydraulic brake, the circular part oi the draught tube 6 above the nozzle, must be emptied of water and this can be affected or assisted by means of a ventilating pipe 11, which upon opening the "alve 12, admits air at atmospheric pressure to the top oi. the draught tube 6. The sluice valve 8 can then be opened to start the jet 13 and bring about the braking ei'lort.

The nozzle consists of a part Owhich is fixed to the draught tube 6 and to the pipe 7. and a part 10 which is screwed to the part 9 so that it forms a removable mouthpiece provided with an internal circular bore suitably tapered and concentric with the axis 15 of the fixed part 9.

It may be advantageous to provide a second mouthpiece 10 interchangeable with the one above referred to'and constructed so as make it easily possible to determine experimentally,after the parts 7 and 9 have been fixed in position, the precise direction in which the jet 13 should be applied to the blades '2 to obtain the best braking action. This second mouthpiece would be provided with an internal circular bore suitably taperedand oilset at a small angle to the axis 15, so that the jet 13 would be slightly deflected from the position shown in Figure 1 in a direction which could be altered according to the angular setting of the mouth piece 10 upon the fixed part 9.

A shield 16 may be provided in the draught tube 6, beneath the nozzle 9, 10 where it projects into this tube, for the pi1rpose of preserving a. proper stream-line ships of the inside surface of the draught tu e.

Referring to the turbine shown in Figure 3 the water is delivered in known manner into thespiral casing 18 and passes thence in a direction radially inwards across the blades 2 of the runner 1 mounted on a. horizontal shaft overhung in bearings. The water on leaving the blades 2 passes out into the draught tube 6, the first part of which is bent through ninety degrees from a horizontal to a vertical plane before it passes through the foundation. The jet 13 of water for braking is delivered from a nozzle 10 :iir-i'ed in the bend of the draught tube 6 at a. point directly in line with the axis oi? the runner 1 and so that it strikes on the conical centre 17 ot the IUDDOIWVlIlCll deflects it laterally on to the blades 2 upon which a clunparatively steady bra-hing thrust is produced. The upper part of the draught tube must of L'OlllSBliQ emptied of water before the hydraulic brake an be brought into Lction.

hat I claim as my invention and desire to secure by Letters Patent 1. A. hydraulic turbine provided with a braking device comprising a runner of the re-atv ion type, a chamber adapted to receive the water flowing out from the runner during normal operation, a nozzle adapted to discharge into said chamber, in the absence of the normal outflow of water from the runner a tree jet which impinges against the runner on the outflow side.

A hydraulic turbine provided with a braking device comprising a runner oi the reaction type, a chamber adapted to receive the water flowing out from the runner during normal operation, a nozzle adapted to discharge through an aperture in the wall of said chamber during; the ab:-;cnce of the normal outflow oil water from the chamber a free jet in a direction having a substantial axial component and impinging upon the runner on its outflow side, means for supplying water under pressure to said nozzle and means 'for controlling-said supply.

3. A hydraulic turbine provided with a bralrii device comprising: a runner 01: the n type a chamber adapted to receive the watei llOVillllj out from the runner during normal working, said chamber being; in the form oi an elbow tube, said tube having); an. aperture subiiu'gantially in line with the axis of the runner a nozzle adaptedto discharge through said a erture a jet of water against therunner when the normal flow of water has been cut oil, means for supplyimi water under prc ire to said nozzle and means i'or controlling said supply.

In testimony whereof I ailix my signature.

PAUL WERNER SEEW' it. 

